纳滤（NF）膜可以高效截留水中的天然有机物、新污染物和多价离子，在饮用水安全保障和污水再生领域展现出广阔的应用前景。但膜的水渗透系数与分离选择性之间的相互制约关系导致系统的运行能耗较高，这限制了NF技术的推广。本论文以制备高透水和截留选择性NF膜为目标，通过对界面聚合过程反应单体的选择和调控，制备了具有高孔隙率分离层和表面强负电势的聚哌嗪酰胺NF膜，突破了传统聚哌嗪酰胺NF膜水渗透系数与选择性之间的相互制约关系。 通过调控界面聚合过程中反应单体的浓度制备了一系列NF膜，发现改变水相哌嗪浓度比正己烷相均苯三甲酰氯浓度对聚哌嗪酰胺分离层结构参数和分离性能的影响更大。分析了分离层结构参数对纳滤膜分离性能的影响，指出了膜孔径对静电作用的影响规律，并建立了聚哌嗪酰胺NF膜水渗透系数与溶质截留选择性之间的相互制约关系。 开发了一种基于增强聚哌嗪酰胺分子链之间空间位阻效应提高分离层孔隙率的方法，在不影响溶质截留能力的条件下显著提高了膜的水渗透系数。利用(R)-2-甲基哌嗪、(S)-2-甲基哌嗪和反式-2,5-二甲基哌嗪单体制备的膜MRPA-0.2%、MSPA-0.2%和MDPA-0.2%水渗透系数分别为14.1±0.1、15.9±0.3和57.8±2.8 L·m?2 h−1 ba?1，膜的切割分子量分别为229 Da、277 Da和607 Da，能突破传统聚哌嗪酰胺NF膜的水渗透系数与中性溶质截留选择性之间的相互制约关系。 利用哌嗪羧酸酯类单体代替甲基哌嗪类单体，制备了一种分离层具有高孔隙率和表面负电位的NF膜，同时提高了膜的水渗透系数和Ca2+/Mg2+与微量有机物分离选择性。其中哌嗪羧酸乙酯制备的膜MEPA对6种测试药物的截留率为61.6%-83.6%，对Ca2+截留率下降为52.2%，水渗透系数是哌嗪制备膜的2.7倍。密度泛函理论计算和单体扩散速率测试结果表明哌嗪羧酸酯类单体增强的扩散能力和氨基差异化的反应能力是形成薄而致密分离层的主要原因。 研究了油相表面活性剂和水相表面活性剂及其浓度对不同构型的二胺（哌嗪、甲基哌嗪、二甲基哌嗪、哌嗪羧酸甲酯）单体界面聚合过程的影响。揭示了结构非对称单体对表面活性剂浓度的依赖效应，为扩宽界面聚合过程中的单体选择提供了指导。

Nanofiltration (NF) membranes can efficiently reject natural organic matters, emerging contaminants and multivalent ions in water, which are considered as promising technologies for drinking water safety and wastewater reclamation. However, the trade-off relationship between water permeability coefficient and selectivity leads to high operational energy consumption of NF water treatment system, which limits the further promotion of NF technology. In this thesis, we prepared polyamide NF membranes with high porosity separation layer and strong negative charged surface through the selection and regulation of reaction monomers in the interfacial polymerization process, which can break through the trade-off relationship between water permeability coefficient and selectivity of traditional poly(piperazine amide) NF membranes. A series of nanofiltration membranes were prepared by regulating the concentration of reaction monomer in the interfacial polymerization process, and it was found that changing the piperazine (PIP) concentration had a greater effect on the structural parameters and separation performance of fabricated membranes than the trimethyl chloride (TMC) concentration. The influence of structural parameters on the separation performance of the NF membrane was discussed and the effect of membrane aperture on the electrostatic action was revealed. This study established the trade-off relationship between the water permeability coefficient and solute rejection selectivity of the poly(piperazine amide) NF membrane. A strategy to enhance the porosity of the active layer based on the enhanced steric hindrance effect between the poly(piperazine amide) chains was proposed for the first time to improve the water permeability coefficient of fabricated membrane without sacrificing the solute rejection selectivity. The water permeability coefficients of MRPA-0.2%, MSPA-0.2% and MDPA-0.2% prepared using (R)-2-methyl piperazine, (S)-2-methyl piperazine and trans-2,5-dimethyl piperazine were 14.1±0.1, 15.9±0.3 and 57.8±2.8 L·m?2 h−1 ba?1, respectively, with cut-off molecular weight of 229 Da, 277 Da and 607 Da, respectively, which can break through the trade-off relationship between the water permeability coefficient and the neutral solute rejection selectivity of the poly(piperazine amide) NF membrane. Based on the above studies, we prepared membranes using piperazine monomers with ester group instead of methyl group, generating sub-nanometer scale voids and carboxyl groups after the hydrolysis of ester group, to improve the porosity of the active layer and enhance the negative potential on membrane surface, aiming to improve the water permeability coefficient and the rejection selectivity between Ca2+/Mg2+ and emerging contaminants of fabricated NF membrane. Among them, the membrane MEPA prepared by piperazine-2-carboxylic acid ethyl ester showed rejection rates of 61.6-83.6% for the six tested pharmaceuticals and 52.2% for Ca2+, respectively. The underlying mechanism of interfacial polymerization of piperazine-2-carboxylic acid ester was investigated through density functional theory calculation and measuring the trans-interface diffusion rate of monomers, and the results showed that the enhanced diffusion ability and the differential reactivity of amino groups were the main reasons for the formation of the thin and dense separation layer. The effects of different types of surfactants, including oil-phase surfactants and aqueous-phase surfactants, and their concentrations on the interfacial polymerization process of different configurations of diamine monomers (piperazine, piperazine with methyl group, piperazine with ester group) were systematically investigated. The dependence effect of structurally asymmetric monomers on surfactant concentration is revealed, which provides guidance for the selection of monomers in the broadening interfacial polymerization process.